Semiconductor device

ABSTRACT

A semiconductor device includes a temperature measurement unit measuring the temperature of a battery cell, a voltage measurement unit measuring the voltage of the battery cell, an electric current measurement unit measuring an electric current supplied from the battery cell, and a control unit. The control unit counts the number of cycles of the charging and discharging of the battery cell, measures the charging rate of the battery cell based on the voltage, measures the internal resistance of the battery cell based on the voltage and the electric current, normalizes the internal resistance based on each of the number of cycles, the temperature, and the charging rate to calculate the shipping internal resistance of the battery cell, and performs, based on the shipping internal resistance, a determination process of whether the battery cell is a non-authenticated product.

CROSS-REFERENCE TO RELATED APPLICATIONS

The disclosure of Japanese Patent Application No. 2017-247451 filed onDec. 25, 2017 including the specification, drawings and abstract isincorporated herein by reference in its entirety.

BACKGROUND

The present invention relates to a semiconductor device.

Rechargeable battery packs are used for various equipment, such as a PC,a DSC, and a DVC. Many non-authenticated battery packs that are lessexpensive than authenticated battery packs are available. Assemblymanufacturers introduce battery authentication technique to detect suchthe non-authenticated battery packs.

In some non-authenticated battery packs, the substrate of an oldauthenticated battery pack that has been disposed of is used, or thedeteriorated battery cell is replaced with a new battery cell. Such thenon-authenticated battery packs pass battery authentication, and thuscannot be effectively detected.

Accordingly, Japanese Unexamined Patent Application Publication No.2013-132147 (Patent Literature 1) discloses an electric storage deviceand the like, which can correctly detect non-authenticated batteryreplacement.

Specifically, the electric storage device has an electric storage unitincluding at least one electric storage element, a measurement unitmeasuring the voltage, the electric current, and the temperature of theelectric storage element, and a calculation unit calculating theinternal resistance of the electric storage element from the voltage,the electric current, and the temperature measured by the measurementunit. And, when detecting the discontinuity of the change with time inthe calculated internal resistance, the electric storage device uses adetermination unit to determine that the electric storage element hasbeen replaced.

More specifically, the electric storage element, such as a lithium ionsecondary battery, has a characteristic in which when the electricstorage element is repeatedly used, the internal resistance increases,so that the electric storage device can detect battery replacement fromthe change in the internal resistance.

SUMMARY

However, to determine the discontinuity of the change with time in theinternal resistance, the electric storage device and the like of PatentLiterature 1 disclose only the internal resistance value increase ordecrease determination method, which determines whether the change inthe measured internal resistance value increases or decreases. On theother hand, the internal resistance value of the authenticated batterypack can be discontinuous due to the deterioration progress when thebattery pack is left in no use and the variation in the use environment.

As a result, even the authenticated battery pack can be falselydetermined to have been replaced with the non-authenticated batterypack, and on the contrary, even the non-authenticated battery pack canbe falsely determined to have been replaced with the authenticatedbattery pack. Therefore, the electric storage device and the like ofPatent Literature 1 cannot correctly detect whether the battery pack isan authenticated product or a non-authenticated product.

Other objects and novel features will be apparent from the descriptionherein and the accompanying drawings.

Semiconductor devices according to a plurality of embodiments aredescribed herein, and the semiconductor device according to one of theembodiments will be described as follows. The semiconductor deviceincludes a temperature measurement unit measuring the temperature of abattery cell, a voltage measurement unit measuring the voltage of thebattery cell, an electric current measurement unit measuring an electriccurrent supplied from the battery cell, and a control unit. The controlunit counts the number of cycles of the charging and discharging of thebattery cell, measures the charging rate of the battery cell based onthe voltage measured by the voltage measurement unit, and measures theinternal resistance of the battery cell based on the voltage and theelectric current measured by the electric current measurement unit. Inaddition, the control unit normalizes the internal resistance based oneach of the number of cycles, the temperature, and the charging rate tocalculate the shipping internal resistance of the battery cell, anddetermines, based on the shipping internal resistance, whether thebattery cell is a non-authenticated product.

According to the one embodiment, the non-authenticated battery cell canbe detected with high accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a circuit diagram illustrating an example of the configurationof a battery pack according to a first embodiment of the presentinvention;

FIGS. 2A to 2C are graphs illustrating the characteristics of theinternal resistance of a battery cell;

FIGS. 3A to 3C are tables illustrating first reference information,second reference information, and third reference information;

FIG. 4 is a chart of assistance in explaining the principle of measuringthe internal resistance of the battery cell;

FIG. 5 is a flowchart illustrating an example of the determinationprocess of the battery cell according to the first embodiment of thepresent invention;

FIG. 6 is a chart illustrating an example of normalized internalresistances according to the first embodiment;

FIG. 7 is a circuit diagram illustrating an example of the configurationof a battery pack according to a second embodiment of the presentinvention;

FIG. 8 is a circuit diagram illustrating an example of the configurationof a battery pack according to a third embodiment of the presentinvention;

FIG. 9 is a table illustrating an example of an internal resistancemanagement table; and

FIG. 10 is a flowchart illustrating an example of the determinationprocess of the battery cell according to the third embodiment of thepresent invention.

DETAILED DESCRIPTION

Embodiments of the present invention will be described below in detailbased on the drawings. Is should be noted that in all the drawings forillustrating the embodiments, the same portions are, as a rule,indicated by similar reference signs, and their repeated description isomitted.

First Embodiment

<The Configuration of a Battery Pack>

FIG. 1 is a circuit diagram illustrating an example of the configurationof a battery pack according to a first embodiment of the presentinvention. As illustrated in FIG. 1, a battery pack 1 includes a batterycell 10, a charging control transistor 12, a discharging controltransistor 14, an electric current detection resistor 16, and a batterypack control circuit (semiconductor device) 20.

The battery pack 1 is a circuit block coupled to a load 90 through apositive side end 1 a and a negative side end 1 b and supplying anelectric current to the load 90.

The battery cell 10 includes a secondary battery, such as a lithiumbattery and a lithium ion battery. The battery cell 10 may include aplurality of secondary batteries coupled in series, as illustrated inFIG. 1, or may include a single secondary battery.

The charging control transistor 12 is a circuit element performingelectric current control during the charging of the battery cell 10. Thecharging control transistor 12 includes a field effect transistor, suchas a MOSFET (Metal Oxide Semiconductor Field Effect Transistor). Asillustrated in FIG. 1, the gate of the charging control transistor 12 iscoupled to the battery pack control circuit 20. The charging controltransistor 12 performs the electric current control during charging bygate voltage control from the battery pack control circuit 20.

The discharging control transistor 14 is a circuit element performingelectric current control during the discharging of the battery cell 10,that is, during the supplying of the electric current to the load 90.The discharging control transistor 14 also includes the field effecttransistor. As illustrated in FIG. 1, the gate of the dischargingcontrol transistor 14 is also coupled to the battery pack controlcircuit 20. The discharging control transistor 14 performs the electriccurrent control during discharging by gate voltage control from thebattery pack control circuit 20.

The electric current detection resistor 16 is a circuit elementdetecting the electric current supplied from the battery cell 10. Theelectric current detection resistor 16 is coupled to the battery packcontrol circuit 20, and the electric current value is measured by alater-described electric current measurement unit 23 provided in thebattery pack control circuit 20.

As illustrated in FIG. 1, the battery pack control circuit 20 includes atemperature measurement unit 21, a voltage measurement unit 22, theelectric current measurement unit 23, a storage unit 24, a charging anddischarging control circuit 25, and a control unit 26.

The temperature measurement unit 21 is a circuit block measuring thetemperature of the battery cell 10. The temperature measurement unit 21includes a temperature sensor and an A/D converter. The A/D converterconverts the temperature measured by the temperature sensor from ananalog signal to a digital signal, and feeds the converted digitalsignal to the control unit 26. The voltage measurement unit 22 is acircuit block measuring the voltage of the battery cell 10. The voltagemeasurement unit 22 may measure the voltage difference between both endsof the battery cell 10 to measure the voltage of the battery cell 10.Alternatively, the voltage measurement unit 22 may measure the potentialdifference between both ends of each of the secondary batteriesconfiguring the battery cell 10 to total the potential differences ofthe respective secondary batteries, thereby calculating the voltage ofthe battery cell 10. The voltage measurement unit 22 includes a voltagemeasurement circuit and an A/D converter. The A/D converter converts thevoltage measured by the voltage measurement circuit from an analogsignal to a digital signal, and feeds the converted digital signal tothe control unit 26.

The electric current measurement unit 23 is a circuit block measuringthe electric current supplied from the battery cell 10. The electriccurrent measurement unit 23 includes an electric current measurementcircuit and an A/D converter. The A/D converter converts the electriccurrent measured by the electric current measurement circuit from ananalog signal to a digital signal, and feeds the converted digitalsignal to the control unit 26.

The storage unit 24 is a circuit block storing various informationrelating to the battery pack 1. The storage unit 24 includes anon-volatile memory, such as a flash memory and an EEPROM.

As illustrated in FIG. 1, the storage unit 24 includes a first referenceinformation storing register 24 a, a second reference informationstoring register 24 b, a third reference information storing register 24c, and a number-of-counts storing register 24 d.

The first reference information storing register 24 a is a registerstoring first reference information associating the number of cycles ofthe charging and discharging of the battery cell 10 with a firstnormalization coefficient. Here, the first normalization coefficient isa coefficient corresponding to the number of cycles, and is acoefficient used for calculating, from the measurement value of theinternal resistance of the battery cell 10, an internal resistance atthe time of shipping (a first shipping internal resistance).

The first reference information storing register 24 a may store, as thefirst reference information, a reference table associating the number ofcycles with the first normalization coefficient, or may store, as thefirst reference information, a normalization function f(Cy) deriving thefirst normalization coefficient in which the number of cycles (Cy) is avariable. It should be noted that the first reference information iswritten into the first reference information storing register 24 abefore the shipping of the battery pack 1.

The second reference information storing register 24 b is a registerstoring second reference information associating the temperature of thebattery cell 10 with a second normalization coefficient. Here, thesecond normalization coefficient is a coefficient corresponding to thetemperature, and is a coefficient used for calculating, from themeasurement value of the internal resistance of the battery cell 10, aninternal resistance at the time of shipping (a second shipping internalresistance).

The second reference information storing register 24 b may store, as thesecond reference information, a reference table associating thetemperature with the second normalization coefficient, or may store, asthe second reference information, a normalization function f(T) derivingthe second normalization coefficient in which the temperature (T) is avariable. It should be noted that the second reference information iswritten into the second reference information storing register 24 bbefore the shipping of the battery pack 1.

The third reference information storing register 24 c is a registerstoring third reference information associating the charging rate of thebattery cell 10 with a third normalization coefficient. Here, the thirdnormalization coefficient is a coefficient corresponding to the chargingrate, and is a coefficient used for calculating, from the measurementvalue of the internal resistance of the battery cell 10, an internalresistance at the time of shipping (a third shipping internalresistance).

The third reference information storing register 24 c may store, as thethird reference information, a reference table associating the chargingrate with the third normalization coefficient, or may store, as thethird reference information, a normalization function f(SoC) derivingthe third normalization coefficient in which the charging rate (SoC:State of Charge) is a variable. It should be noted that the thirdreference information is written into the third reference informationstoring register 24 c before the shipping of the battery pack 1.

The number-of-counts storing register 24 d is a register storing thenumber of cycles of the charging and discharging of the battery cell 10.Information of the number of cycles stored in the number-of-cyclesstoring register 24 d is supplied from the control unit 26.Alternatively, the number-of-counts storing register 24 d may include acounter. In this case, the counter counts, as the number of cycles, thenumber of times in which the count signal is asserted from the controlunit 26.

In addition, the storage unit 24 includes, other than these registers,for example, various registers, such as a register storing the allowablerange of the shipping internal resistance of the battery cell 10 allowedas an authenticated product, and a register storing the voltage of thebattery cell 10 during full charging.

Examples of the Characteristics of the Internal Resistance of theBattery Cell and the Normalization Coefficients

Here, examples of the characteristics of the internal resistance of thebattery cell, the first normalization coefficient, the secondnormalization coefficient, and the third normalization coefficient willbe described here with reference to FIGS. 2A to 3C.

FIGS. 2A to 2C are graphs illustrating the characteristics of theinternal resistance of the battery cell. FIG. 2A is a graph illustratingthe cycle characteristic of the internal resistance. FIG. 2B is a graphillustrating the temperature characteristic of the internal resistance.FIG. 2C is a graph illustrating the charging rate (SoC) characteristicof the internal resistance.

On the other hand, FIGS. 3A to 3C are tables illustrating the firstreference information, the second reference information, and the thirdreference information. FIG. 3A is a table illustrating the referencetable associating the number of cycles of the battery cell 10 with thefirst normalization coefficient. FIG. 3B is a table illustrating thereference table associating the temperature of the battery cell 10 withthe second normalization coefficient. FIG. 3C illustrates the referencetable associating the charging rate of the battery cell 10 with thethird normalization coefficient.

First, the number-of-cycles characteristic of the battery cell 10 willbe described. As illustrated in FIG. 2A, as the number of cyclesincreases, the internal resistance of the battery cell 10 becomeshigher. Further, as the number of cycles increases, the increase rate ofthe internal resistance becomes higher.

On the other hand, the number of cycles is one (Cy=1) at the time of theshipping of the battery pack 1, and as illustrated in FIG. 3A, the firstnormalization coefficient is set to 1. When the number of cycles is 250,for example, the first normalization coefficient is set to K1 (K1<1).Hereinbelow, as the number of cycles increases, the respective firstnormalization coefficients are further set to smaller values K2 and K3(K1>K2>K3). And, when the number of cycles is 1000, for example, thefirst normalization coefficient is set to K4 (K4<K3).

Next, the temperature characteristic of the battery cell will bedescribed. As illustrated in FIG. 2B, as the temperature increases, theinternal resistance of the battery cell 10 becomes lower. Further, asthe temperature lowers, the lowering rate of the internal resistancebecomes higher.

On the other hand, when the temperature of the battery cell 10 is 25° C.(T=25) at the time of the shipping of the battery pack 1, the secondnormalization coefficient at this temperature is set to 1, asillustrated in FIG. 3B. When the temperature is 0° C., for example, thesecond normalization coefficient is set to K12 (K12<1). Further, whenthe temperature is −20° C., for example, the second normalizationcoefficient is set to K11 (K11<K12). Furthermore, when the temperaturesare 40° C. and 60° C., for example, the respective second normalizationcoefficients are set to K13 and K14 (1<K13<K14).

Next, the charging rate characteristic of the battery cell 10 will bedescribed. As illustrated in FIG. 2C, as the charging rate lowers, theinternal resistance of the battery cell 10 becomes higher. In addition,as the charging rate lowers, the increase rate of the internalresistance becomes higher.

On the other hand, when the charging rate of the battery cell 10 is 60%(SoC=60) at the time of the shipping of the battery pack 1, the thirdnormalization coefficient at this charging rate is set to 1, asillustrated in FIG. 3C. When the charging rates are 40% and 20%, forexample, the respective third normalization coefficients are set to K23and K24 (K24<K23<1). On the other hand, when the charging rates are 80%and 100%, the respective third normalization coefficients are set to K22and K21 (1<K22<K21).

It should be noted that the characteristics of the battery cell 10 arenot limited to such the examples. For example, contrary to the examplesin FIGS. 2A and 3A, as the number of cycles increases, the internalresistance of the battery cell 10 can be lower. In addition, contrary tothe examples in FIGS. 2B and 3B, as the temperature increases, theinternal resistance of the battery cell 10 can be higher. Further,contrary to the examples in FIGS. 2C and 3C, as the charging ratelowers, the internal resistance of the battery cell 10 can be higher.

Here, the description of the battery pack control circuit 20 will bereturned. The charging and discharging control circuit 25 is a circuitblock controlling the electric current during the charging anddischarging of the battery cell 10. Specifically, the charging anddischarging control circuit 25 controls the gate voltages of thecharging control transistor 12 and the discharging control transistor 14to control the electric current during charging and discharging.

The control unit 26 is a circuit controlling each operation of thebattery pack control circuit 20. For example, the control unit 26 feedsthe electric current control signal to the charging and dischargingcontrol circuit 25 to control the electric current during the chargingand discharging of the battery cell 10. In addition, the control unit 26counts the number of cycles of the charging and discharging of thebattery cell 10 to store the counted number of cycles in thenumber-of-counts storing register 24 d. Alternatively, when the chargingrate of the battery cell 10 is reached, the control unit 26 may assertthe count signal.

In addition, the control unit 26 measures the charging rate of thebattery cell 10. Specifically, the control unit 26 calculates thecharging rate of the battery cell 10 based on the voltage of the batterycell 10 measured by the voltage measurement unit 22 and the voltage ofthe battery cell 10 during full charging. In addition, the control unit26 measures the internal resistance of the battery cell 10.Specifically, the control unit 26 measures the internal resistance ofthe battery cell 10 based on the measured voltage of the battery cell 10and the electric current of the battery cell 10 measured by the electriccurrent measurement unit 23.

FIG. 4 is a chart of assistance in explaining the principle of measuringthe internal resistance of the battery cell. The upper stage of FIG. 4is a timing chart illustrating the variation in the voltage of thebattery cell 10. The lower stage of FIG. 4 is a timing chartillustrating the variation in the electric current of the battery cell10.

When discharging is started at time t1, the voltage of the battery cell10 suddenly lowers from V0 to V1, as illustrated in FIG. 4. On the otherhand, the electric current supplied from the battery cell 10 suddenlyincreases from I0 to I1. At this time, the voltage of the battery cell10 is influenced mainly by the direct current resistance component ofthe internal resistance.

Thereafter, during the period until time t2, the voltage of the batterycell 10 gently lowers from V1 to V2. On the other hand, the electriccurrent remains at I1, and hardly varies. During this period, thevoltage of the battery cell 10 is influenced mainly by the polarizationresistance component of the internal resistance. After the voltage isinfluenced by the polarization resistance component and is settled, thecontrol unit 26 measures the internal resistance of the battery cell 10.Therefore, the control unit 26 measures the internal resistance of thebattery cell 10 from the voltage difference ΔV (=V0−V2) between the timet1 and the time t2 and the electric current difference ΔI (=I1−I0)during this period.

In addition, the control unit 26 normalizes the internal resistancebased on each of the number of cycles, the temperature, and the chargingrate of the battery cell 10, and calculates the internal resistance atthe time of the shipping of the battery cell 10 (hereinafter, alsocalled a shipping internal resistance).

In addition, the control unit 26 determines, based on the calculatedshipping internal resistance, whether the battery cell 10 is anon-authenticated product. These processes will be described later.

<The Determination Process of the Battery Cell>

Next, the determination process of the battery cell 10 will bedescribed. FIG. 5 is a flowchart illustrating an example of thedetermination process of the battery cell according to the firstembodiment of the present invention. The determination process of thebattery cell 10 is performed in steps S10 to S50 illustrated in FIG. 5.

Step S10

Step S10 is a step of starting the supplying of the electric current tothe load 90. When the power supply of the load 90 is turned on, thebattery pack 1 supplies the electric current to the load 90.Specifically, the charging and discharging control circuit 25 controlsthe gate voltages of the charging control transistor 12 and thedischarging control transistor 14 based on the electric current controlsignal fed from the control unit 26, thereby supplying the electriccurrent to the load 90.

Step S20

Step S20 is a step of reading various information used for thedetermination process of the battery cell 10. Specifically, the controlunit 26 reads the first reference information, the second referenceinformation, and the third reference information from the firstreference information storing register 24 a, the second referenceinformation storing register 24 b, and the third reference informationstoring register 24 c, respectively. In addition, the control unit 26reads the number of cycles of the charging and discharging from thenumber-of-counts storing register 24 d.

In addition, the control unit 26 reads, from the storage unit 24, theallowable range of the shipping internal resistance of the battery cell10, the voltage of the battery cell 10 during full charging, and thelike. The control unit 26 buffers, in its interior, these variousinformation read from the storage unit 24.

Step S30

Step S30 is a step of measuring the internal resistance and the like ofthe battery cell 10. When the control unit 26 asserts the voltagemeasurement signal, the voltage measurement unit 22 measures the voltageof the battery cell 10, thereby supplying the measured voltage to thecontrol unit 26. In addition, when the control unit 26 asserts theelectric current measurement signal, the electric current measurementunit 23 measures the electric current supplied from the battery cell 10,thereby supplying the measured electric current to the control unit 26.

In addition, when the control unit 26 asserts the temperaturemeasurement signal, the temperature measurement unit 21 measures thetemperature of the battery cell 10, thereby supplying the measuredtemperature to the control unit 26.

And, the control unit 26 calculates the internal resistance of thebattery cell 10 based on the measured voltage and electric current. Inaddition, the control unit 26 calculates the charging rate of thebattery cell 10 based on the measured voltage and the voltage of thebattery cell 10 during full charging.

It should be noted that the timing at which the voltage is measured andthe timing at which the electric current is measured are desirablysubstantially the same. With this, the more correct internal resistancecan be measured. In addition, the timing at which the temperature ismeasured is preferably substantially the same as the timing at which thevoltage is measured and the timing at which the electric current ismeasured. With this, the more appropriate normalization coefficient isselected, so that the more correct shipping internal resistance can becalculated.

Step S40

Step S40 is a step of calculating the shipping internal resistance. Thecontrol unit 26 derives, from the first reference information, the firstnormalization coefficient corresponding to the read number of cycles ofthe battery cell 10. And, the control unit 26 multiplies the internalresistance of the battery cell 10 measured in step S30 by the derivedfirst normalization coefficient to calculate the first shipping internalresistance.

In addition, the control unit 26 derives, from the second referenceinformation, the second normalization coefficient corresponding to thetemperature measured in step S30. And, the control unit 26 multipliesthe internal resistance of the battery cell 10 measured in step S30 bythe derived second normalization coefficient to calculate the secondshipping internal resistance.

In addition, the control unit 26 derives, from the third referenceinformation, the third normalization coefficient corresponding to thecharging rate measured in step S30. And, the control unit 26 multipliesthe internal resistance of the battery cell 10 measured in step S30 bythe derived third normalization coefficient to calculate the thirdshipping internal resistance.

Step S50

Step S50 is a step of determining whether the battery cell 10 is anon-authenticated product. The control unit 26 compares each of thefirst shipping internal resistance, the second shipping internalresistance, and the third shipping internal resistance with theallowable range of the shipping internal resistance read in step S20.And, when any one of the first shipping internal resistance, the secondshipping internal resistance, and the third shipping internal resistanceis outside the allowable range (No), the control unit 26 determines thatthe battery cell 10 to be determined is a non-authenticated product.

On the other hand, when all of the first shipping internal resistance,the second shipping internal resistance, and the third shipping internalresistance are within the allowable range (Yes), the control unit 26determines that the battery cell 10 to be determined is an authenticatedproduct. In this case, as illustrated in FIG. 5, the control unit 26repeatedly executes steps S30 to S50, and successively performs thedetermination process of whether the battery cell 10 is anon-authenticated product.

It should be noted that the determination process of the battery cell 10is not limited to such the case. For example, the control unit 26 maydirectly read the first normalization coefficient corresponding to thenumber of cycles from the first reference information storing register24 a, may directly read the second normalization coefficientcorresponding to the temperature from the second reference informationstoring register 24 b, and may directly read the third normalizationcoefficient corresponding to the charging rate from the third referenceinformation storing register 24 c.

An Example of the Determination Process of the Battery Cell

FIG. 6 is a chart illustrating an example of the normalized internalresistances according to the first embodiment. The abscissa axis in FIG.6 represents the time, and the ordinate axis in FIG. 6 represents theinternal resistance (the calculated shipping internal resistance). FIG.6 illustrates the minimum value (Rref minimum value) and the maximumvalue (Rref maximum value) of a shipping internal resistance Rref. And,the allowable range of the shipping internal resistance is defined fromthe minimum value to the maximum value of the shipping internalresistance.

Respective resistance values R1 to R7 illustrated in FIG. 6 are theshipping internal resistances calculated at the respective differenttimes. As illustrated in FIG. 6, the resistance values R1 to R6 arewithin the allowable range, and in this case, the control unit 26determines that the battery cell 10 to be determined is an authenticatedproduct. On the other hand, the resistance value R7 calculated at timet7 is below the minimum value of the allowable range, and thus, thecontrol unit 26 determines that the battery cell 10 to be determined isa non-authenticated product. That is, the control unit 26 determinesthat the replacement of the battery cell has occurred during thisperiod.

Effects According to this Embodiment

Here, main effects according to this embodiment will be described.According to this embodiment, the control unit 26 calculates the firstshipping internal resistance of the battery cell 10 based on the numberof cycles of the battery cell 10, the control unit 26 calculates thesecond shipping internal resistance of the battery cell 10 based on thetemperature of the battery cell 10, and the control unit 26 calculatesthe third shipping internal resistance of the battery cell 10 based onthe charging rate of the battery cell 10. And, the control unit 26compares each of the first shipping internal resistance, the secondshipping internal resistance, and the third shipping internal resistancewith the allowable range of the shipping internal resistance, and whenany one of the shipping internal resistances is outside the allowablerange, the control unit 26 determines that the battery cell 10 is anon-authenticated product.

According to this configuration, the internal resistance at the time ofthe shipping of the battery cell 10 can be estimated from themeasurement value of each of the number of cycles, the temperature, thecharging rate, and the internal resistance, so that thenon-authenticated battery cell can be detected with high accuracy. Also,it is possible to detect the non-authenticated battery cell withoutcontinuously performing the calculation and comparison of the shippinginternal resistance of the battery cell. Also, the replacement of theauthenticated battery cell with the non-authenticated battery cell canbe detected with high accuracy. Also, since the discontinuity of theinternal resistance is not required to be considered, the determinationprocess can be easily executed.

Also, according to this embodiment, the control unit 26 multiplies thefirst normalization coefficient by the measured internal resistance tocalculate the first shipping internal resistance of the battery cell 10,multiplies the second normalization coefficient by the measured internalresistance to calculate the second shipping internal resistance of thebattery cell 10, and multiplies the third normalization coefficientcorresponding to the charging rate by the measured internal resistanceto calculate the third shipping internal resistance of the battery cell10.

According to this configuration, the process for calculating the firstshipping internal resistance, the second shipping internal resistance,and the third shipping internal resistance can be simplified, so thatthe load of the control unit 26 is reduced and the determination processis faster.

Also, according to this embodiment, the control unit 26 derives thefirst normalization coefficient corresponding to the number of cyclesfrom the first reference information, derives the second normalizationcoefficient corresponding to the measured temperature from the secondreference information, and derives the third normalization coefficientcorresponding to the measured charging rate from the third referenceinformation. Also in this configuration, the process for deriving thefirst normalization coefficient, the second normalization coefficient,and the third normalization coefficient can be simplified, so that theload of the control unit 26 is reduced and the determination process isfaster.

Also, according to this embodiment, the first reference information, thesecond reference information, the third reference information includethe tables. According to this embodiment, also in this configuration,the process for deriving the first normalization coefficient, the secondnormalization coefficient, and the third normalization coefficient canbe simplified, so that the load of the control unit 26 is reduced andthe determination process is faster.

Also, according to this embodiment, the first reference information, thesecond reference information, the third reference information includethe normalization coefficients. Also in this configuration, the capacityof the first reference information storing register 24 a, the secondreference information storing register 24 b, and the third referenceinformation storing register 24 c can be reduced.

Also, according to this embodiment, the first reference information, thesecond reference information, and the third reference information arewritten into the first reference information storing register 24 a, thesecond reference information storing register 24 b, and the thirdreference information storing register 24 c, respectively, before theshipping of the battery cell 10. According to this configuration, thefirst reference information, the second reference information, the thirdreference information are not required to be obtained in eachdetermination process, so that the determination process is faster.

Also, according to this embodiment, even when determining that thebattery cell 10 is an authenticated product, the control unit 26calculates the first shipping internal resistance, the second shippinginternal resistance, and the third shipping internal resistance again,and performs the determination process of the battery cell 10. Accordingto this configuration, even if the battery cell 10 is falsely determinedto be an authenticated product in the previous determination process,the determination process is performed with respect to the same batterycell 10 again, so that the accuracy of the determination process can befurther improved.

Second Embodiment

Next, a second embodiment of the present invention will be described. Inthe first embodiment, the shipping internal resistance corresponding toeach of the number of cycles, the temperature, and the charging rate andthe allowable range of the shipping internal resistance are comparedindividually. In this case, the measured internal resistance depends oneach of the number of cycles, the temperature, and the charging rate,but the first normalization coefficient, the second normalizationcoefficient, and the third normalization coefficient are mutuallyindependent between the number of cycles, the temperature, and thecharging rate. Consequently, the case where the accuracy of thecalculated first shipping internal resistance, the calculated secondshipping internal resistance, and the calculated third shipping internalresistance is not sufficiently secured can occur.

Accordingly, in this embodiment, the case where the normalizationcoefficient in consideration of a combination of the number of cycles,the temperature, and the charging rate is derived to perform thedetermination process of the battery cell 10 will be described.Hereinbelow, it should be noted that the description of the portionsoverlapped with the above embodiment is omitted as a rule.

FIG. 7 is a circuit diagram illustrating an example of the configurationof a battery pack according to the second embodiment of the presentinvention. In a battery pack 201 illustrated in FIG. 7, the battery packcontrol circuit 20 illustrated in FIG. 1 is replaced with a battery packcontrol circuit 220. And, in the battery pack control circuit 220, thestorage unit 24 illustrated in FIG. 1 is replaced with a storage unit224. Specifically, in the storage unit 224, a fourth referenceinformation storing register 224 e is added to the storage unit 24illustrated in FIG. 1.

The fourth reference information storing register 224 e is a registerstoring fourth reference information associating a combination of thenumber of cycles, the temperature, and the charging rate of the batterycell 10 with a fourth normalization coefficient. Here, the fourthnormalization coefficient is a coefficient corresponding to acombination of the number of cycles, the temperature, and the chargingrate, and is a coefficient used for calculating, from the measurementvalue of the internal resistance of the battery cell 10, an internalresistance at the time of shipping (a fourth shipping internalresistance).

The fourth reference information storing register 224 e may store, asthe fourth reference information, a reference table associating acombination of the number of cycles, the temperature, and the chargingrate with the fourth normalization coefficient, or may store, as thefourth reference information, a normalization function f(Cy, T, SoC)deriving the fourth normalization coefficient in which the number ofcycles (Cy), the temperature (T), and the charging rate (SoC) are asvariables. It should be noted that the fourth reference information iswritten into the fourth reference information storing register 224 ebefore the shipping of the battery pack 1.

<The Determination Process of the Battery Cell>

Next, the determination process of the battery cell 10 according to thisembodiment will be described along FIG. 5. It should be noted that stepsS10 and S30 are the same as the first embodiment, and their descriptionis omitted.

In step S20, the control unit 26 reads the already described fourthreference information from the fourth reference information storingregister 224 e. In addition, the processes other than this are the sameas the first embodiment.

In step S40, the control unit 26 derives, from the fourth referenceinformation, the fourth normalization coefficient corresponding to acombination of the read number of cycles of the battery cell 10, themeasured internal resistance of the battery cell 10, and the measuredcharging rate of the battery cell 10. And, the control unit 26multiplies the internal resistance of the battery cell 10 measured instep S30 by the derived fourth normalization coefficient to calculatethe fourth shipping internal resistance.

In addition, other than the method described here, the control unit 26may multiply the first normalization coefficient, the secondnormalization coefficient, and the third normalization coefficientderived in step S40 in the first embodiment to derive the fourthnormalization coefficient. For example, when the fourth referenceinformation includes the normalization coefficient f(Cy, T, SoC), thefourth normalization coefficient is f(Cy, T, SoC)=f(Cy)×f(T)×f(SoC).

In step S50, the control unit 26 compares the fourth shipping internalresistance with the allowable range of the shipping internal resistanceread in step S20. And, when the fourth shipping internal resistance isoutside the allowable range, the control unit 26 determines that thebattery cell 10 is a non-authenticated product.

On the other hand, when determining that the battery cell 10 is anauthenticated product, the control unit 26 repeatedly executes steps S30to S50, as illustrated in FIG. 5, and successively performs thedetermination process of whether the battery cell 10 is anon-authenticated product.

Main Effects According to this Embodiment

According to this embodiment, in addition to the already describedeffects, the following effects can be obtained. According to thisembodiment, the shipping internal resistance based on a combination ofthe number of cycles, the temperature, and the charging rate can becalculated, so that the determination process of the battery cell 10 canbe executed with higher accuracy.

Third Embodiment

Next, a third embodiment of the present invention will be described. Inthe above embodiments, the measured internal resistance is normalized tocalculate the shipping internal resistance, and the determinationprocess of the battery cell 10 of whether the shipping internalresistance is within the allowable range is performed. On the contrary,in this embodiment, the measured internal resistance is recorded into apredetermined management table to compare the measured internalresistance with the internal resistance recorded into the table, therebyperforming the determination process of the battery cell 10. That is, inthis embodiment, the determination process of the battery cell 10 isperformed without normalizing the measured internal resistance.

FIG. 8 is a circuit diagram illustrating an example of the configurationof a battery pack according to the third embodiment of the presentinvention. In addition, FIG. 9 is a table illustrating an example of aninternal resistance management table. In a battery pack 301 illustratedin FIG. 8, the battery pack control circuit 20 illustrated in FIG. 1 isreplaced with a battery pack control circuit 320. And, in the batterypack control circuit 320, the storage unit 24 illustrated in FIG. 1 isreplaced with a storage unit 324. Specifically, in the storage unit 324,an internal resistance management table storing register 324 f is addedto the storage unit 24 illustrated in FIG. 1.

The internal resistance management table storing register 324 f is aregister storing an internal resistance management table 350 illustratedin FIG. 9. As illustrated in FIG. 9, the internal resistance managementtable 350 includes a temperature recording axis (abscissa axis) and acharging rate recording axis (ordinate axis). The internal resistancemanagement table 350 records the measured internal resistance so as toassociate the measured internal resistance with the temperature and thecharging rate during measurement. The internal resistance managementtable 350 records the measured internal resistance only when the batterycell to be determined is determined to be an authenticated product. Theinternal resistance management table 350 may be stored in the internalresistance management table storing register 324 f before the shippingof the battery cell 10.

Specifically, another authenticated battery cell before shipping is usedto measure the internal resistance in a state where the conditions ofthe temperature and the charging rate are made different. It should benoted that the number of cycles at this time is “1”. And, the internalresistance management table is created based on the internal resistancemeasured under the respective conditions, and the created internalresistance management table is then stored in the internal resistancemanagement table storing register 324 f of the battery pack shipped. Itshould be noted that during the creation of the internal resistancemanagement table, the internal resistances of a plurality ofauthenticated battery cells may be measured to create the internalresistance management table based on the value obtained by calculatingthe average of these.

In addition, other than these registers, for example, the storage unit324 includes various registers, such as a register storing a differenceallowable range allowed as an authenticated product.

Here, the difference allowable range will be described. The differenceallowable range is information used for determining whether the batterycell 10 to be determined is a non-authenticated product. When theinternal resistance at the same temperature and at the same chargingrate is measured again, the control unit 26 compares the measuredinternal resistance with the corresponding internal resistance recordedinto the internal resistance management table 350, and performs thedetermination process of whether the battery cell 10 is anon-authenticated product.

Specifically, the control unit 26 calculates the difference between themeasured internal resistance and the internal resistance recorded intothe internal resistance management table 350, and compares thedifference with the difference allowable range. And, when the calculateddifference is within the difference allowable range, the control unit 26determines that the battery cell 10 to be determined is an authenticatedproduct, and when the calculated difference is outside the differenceallowable range, the control unit 26 determines that the battery cell 10to be determined is a non-authenticated product. In this way, thedifference allowable range is used for the determination process of thebattery cell 10.

It should be noted that as already described in connection with FIG. 2A,as the number of cycles increases, the increase rate of the internalresistance becomes higher. Thus, as the number of cycles increases, thedifference is considered to become larger, so that when the number ofcycles reaches a predetermined number of times, the difference allowablerange may be switched to the larger difference allowable range toexecute the determination process.

Attitude to this Embodiment

The allowable range used in the above embodiments is defined in thesection from the minimum value (Rref minimum) to the maximum value (Rrefmaximum) of the shipping internal resistance Rref. In addition, asalready described, from the measured internal resistance Rcel of thebattery cell 10 and the normalization coefficient f (Cy, T, SoC), theshipping internal resistance Rref is Rref=Rcel×f (Cy, T, SoC).

When this equation is applied to the conditions of the allowable rangeof the shipping internal resistance Rref, Rcel×f (Cy, T, SoC) is “Rrefminimum<Rcel×f (Cy, T, SoC)<Rref maximum”. When this equation is furtherrearranged, the Rcel is “Rref minimum/f (Cy, T, SoC)<Rcel<Rref maximum/f(Cy, T, SoC)”.

Rref/f (Cy, T, SoC) represented here is obtained by non-normalizing theoriginal internal resistance of the battery cell 10, that is, theinternal resistance measurement value of the battery cell 10 dependingon the respective conditions of the number of cycles, the temperature,and the charging rate. In the attitude to this embodiment, when themeasured internal resistance is within the range from Rref minimum/f(Cy,T, SoC) to Rref maximum/f(Cy, T, SoC), the battery cell 10 is anauthenticated product.

However, in one cycle or several cycles, the internal resistancemeasurement value does not greatly increase, and the number of cyclesdoes not decrease, so that the internal resistance management tablerecords the measured internal resistance by using the temperature andthe charging rate as the recording axes. Thus, when chronologicallyobserved, the internal resistance measured under the same conditions canbe considered to be the function in which the number of cycles is avariable.

<The Determination Process of the Battery Cell>

Next, the determination process of the battery cell 10 according to thisembodiment will be described. FIG. 10 is a flowchart illustrating anexample of the determination process of the battery cell according tothe third embodiment of the present invention. As illustrated in FIG.10, the determination process of the battery cell 10 according to thisembodiment is performed in steps S10 to S360. It should be noted thatsteps S10 and S30 are the same as the first and second embodiments, andtheir description is omitted.

Step S320

Step S320 is similar to step S20 in FIG. 5, and is a step of readingvarious information used for the determination process of the batterycell 10. Specifically, the control unit 26 reads the internal resistancemanagement table 350 from the internal resistance management tablestoring register 324 f. In addition, the control unit 26 reads thedifference allowable range, the voltage of the battery cell 10 duringfull charging, and the like, from the storage unit 24. The control unit26 buffers, in its interior, these various information read from thestorage unit 24.

Steps S350 and S360

Step S350 is a step of determining whether the battery cell 10 is anon-authenticated product.

When measuring the internal resistance of the battery cell 10 and theconditions during measurement (the temperature and the charging rate) instep S30, the control unit 26 compares the measured internal resistancewith the corresponding internal resistance recorded into the internalresistance management table 350, and performs the determination processof whether the battery cell 10 to be determined is a non-authenticatedproduct. Specifically, the difference between the measured internalresistance and the corresponding internal resistance recorded into theinternal resistance management table 350 is calculated to compare thedifference with the difference allowable range. When the difference isoutside the difference allowable range (No), the control unit 26determines that the battery cell 10 to be determined is anon-authenticated product.

On the other hand, when the difference is within the differenceallowable range (Yes), the control unit 26 determines that the batterycell 10 to be determined is an authenticated product. In this case, thecontrol unit 26 executes the process in step S360. Step S360 is a stepof recording the measured internal resistance into the internalresistance management table 350. The control unit 26 records themeasured internal resistance into the corresponding portion of theinternal resistance management table 350.

For example, as illustrated in FIG. 9, an internal resistance R11corresponding to the temperature=0° C. and the charging rate=50% isrecorded into the internal resistance management table 350. Assume thatthe control unit 26 measures a new internal resistance R21 under thesame conditions. At this time, when the battery cell 10 is determined tobe an authenticated product, the control 26 updates the originalinternal resistance R11 recorded into the internal resistance managementtable 350 to the new internal resistance R21.

When step S360 is completed, the control unit 26 repeatedly executessteps S30 to S350, as illustrated in FIG. 10, and successively performsthe determination process of whether the battery cell 10 is anon-authenticated product.

It should be noted that also in this embodiment, the determinationprocess of the battery cell 10 is not limited to such the case. Forexample, the control unit 26 may directly read the internal resistancemanagement table 350 from the internal resistance management tablestoring register 324 f, or may directly update the internal resistancemanagement table stored in the internal resistance management tablestoring register 324 f.

The case where the temperature recording axis corresponding to thetemperature during measurement is not provided

The process in the case where the temperature recording axiscorresponding to the temperature during measurement is not provided willbe described with reference to FIG. 9.

When the temperature recording axis corresponding to the temperatureduring measurement is not provided, the control unit 26 calculates atemperature interpolation internal resistance based on the internalresistance corresponding to the temperature during measurement on eachof the temperature recording axes corresponding to a plurality oftemperatures near the temperature during measurement.

For example, assume that the internal resistance is measured under thetemperature=15° C. and the charging rate=80%. However, the temperaturerecording axis corresponding to 15° C. is not provided in the internalresistance management table 350, so that here, liner interpolation isperformed based on an internal resistance R12 corresponding to thetemperature=10° C. and the charging rate=80% and an internal resistanceR13 corresponding to the temperature=20° C. and the charging rate=80%,and an internal resistance corresponding to the temperature=15° C. andthe charging rate=80% (temperature interpolation internal resistance) isthen calculated.

And, the control unit 26 calculates the difference between the measuredinternal resistance and the temperature interpolation internalresistance, and compares the difference with the difference allowablerange, thereby performing the determination process of the battery cell10.

The case where the charging rate recording axis corresponding to thecharging rate during measurement is not provided

The same process as the process with respect to the temperature isperformed with respect to the charging rate.

When the charging rate recording axis corresponding to the charging rateduring measurement is not provided, the control unit 26 calculates acharging rate interpolation internal resistance based on the internalresistance corresponding to the charging rate during measurement on eachof the charging rate recording axes corresponding to a plurality ofcharging rates near the charging rate during measurement.

For example, assume that the internal resistance is measured under theconditions of the temperature=20° C. and the charging rate=95%. However,the charging rate recording axis corresponding to 95% is not provided inthe internal resistance management table 350, so that here, linerinterpolation is performed based on an internal resistance R14corresponding to the temperature=20° C. and the charging rate=90% and aninternal resistance R15 corresponding to the temperature=20° C. and thecharging rate=100%, and an internal resistance corresponding to thetemperature=20° C. and the charging rate=95% (charging rateinterpolation internal resistance) is then calculated.

And, the control unit 26 calculates the difference between the measuredinternal resistance and the charging rate interpolation internalresistance, and compares the difference with the difference allowablerange, thereby performing the determination process of the battery cell10.

[The Case where the Recording Axes Corresponding to the Temperature andthe Charging Rate During Measurement are not Provided]

Of course, there can also be the case where the recording axescorresponding to both of the temperature and the charging rate duringmeasurement are not provided. In this case, an internal resistance(temperature and charging rate interpolation internal resistance) iscalculated based on the internal resistance corresponding to thetemperature and the charging rate during measurement on each of thetemperature recording axes and each of the charging rate recording axescorresponding to a plurality of temperatures and a plurality of chargingrates near the conditions during measurement.

For example, when the internal resistance is measured under theconditions of the temperature=15° C. and the charging rate=85%, linerinterpolation is performed based on the internal resistance R12corresponding to the temperature=10° C. and the charging rate=80% andthe internal resistance R14 corresponding to the temperature=20° C. andthe charging rate=90%, and a corresponding internal resistance(temperature and charging rate interpolation internal resistance) isthen calculated. Alternatively, liner interpolation may be performedbased on an internal resistance R16 corresponding to the temperature=10°C. and the charging rate=90% and the internal resistance R13corresponding to the temperature=20° C. and the charging rate=80%, andthe corresponding internal resistance may then be calculated. Further,the corresponding internal resistance may be calculated based on theinternal resistances R12 to R14 and R16 under the respective conditionssurrounding the measurement conditions.

Main Effects According to this Embodiment

According to this embodiment, the determination process can be performedwithout normalizing the measured internal resistance, so that the loadof the control unit 26 is reduced.

Also, the internal resistance under the condition in which the recordingaxis is not provided can be calculated by linear interpolation, so thatthe determination process under each condition can be executed while theamount of data of the internal resistance management table 350 isreduced.

Also, at the time of shipping, the internal resistance management table350 is stored in the battery pack 1, so that the determination processaccording to this embodiment can be executed immediately after the useis started.

The inventions made by the present inventors have been specificallydescribed above based on the embodiments, but the present invention isnot limited to the embodiments, and needless to say, variousmodifications can be made in the scope not departing from its purport.

What is claimed is:
 1. A semiconductor device comprising: a temperaturemeasurement unit measuring the temperature of a battery cell; a voltagemeasurement unit measuring the voltage of the battery cell; an electriccurrent measurement unit measuring an electric current supplied from thebattery cell; and a control unit, wherein the control unit counts thenumber of cycles of the charging and discharging of the battery cell,measures the charging rate of the battery cell based on the voltage,measures the internal resistance of the battery cell based on thevoltage and the electric current, normalizes the internal resistancebased on each of the number of cycles, the temperature, and the chargingrate to calculate the shipping internal resistance of the battery cell,and performs, based on the shipping internal resistance, a determinationprocess of whether the battery cell is a non-authenticated product. 2.The semiconductor device according to claim 1, wherein the control unitmultiplies a first normalization coefficient corresponding to the numberof cycles by the internal resistance to calculate a first shippinginternal resistance, multiplies a second normalization coefficientcorresponding to the temperature by the internal resistance to calculatea second shipping internal resistance, multiplies a third normalizationcoefficient corresponding to the charging rate by the internalresistance to calculate a third shipping internal resistance, andperforms the determination process based on the first shipping internalresistance, the second shipping internal resistance, and the thirdshipping internal resistance.
 3. The semiconductor device according toclaim 2, wherein the control unit derives the first normalizationcoefficient corresponding to the counted number of cycles from firstreference information associating the number of cycles with the firstnormalization coefficient, derives the second normalization coefficientcorresponding to the measured temperature from second referenceinformation associating the temperature with the second normalizationcoefficient, and derives the third normalization coefficientcorresponding to the measured charging rate from third referenceinformation associating the charging rate with the third normalizationcoefficient.
 4. The semiconductor device according to claim 3, whereinthe first reference information includes a table associating the numberof cycles with the first normalization coefficient, wherein the secondreference information includes a table associating the temperature withthe second normalization coefficient, wherein the third referenceinformation includes a table associating the charging rate with thethird normalization coefficient.
 5. The semiconductor device accordingto claim 3, wherein the first reference information includes a functionderiving the first normalization coefficient in which the number ofcycles is a variable, wherein the second reference information includesa function deriving the second normalization coefficient in which thetemperature is a variable, wherein the third reference informationincludes a function deriving the third normalization coefficient inwhich the charging rate is a variable.
 6. The semiconductor deviceaccording to claim 2, wherein the control unit compares each of thefirst shipping internal resistance, the second shipping internalresistance, and the third shipping internal resistance with theallowable range of the shipping internal resistance allowed as anauthenticated product, and when any one of the first shipping internalresistance, the second shipping internal resistance, and the thirdshipping internal resistance is outside the allowable range, the controlunit determines that the battery cell is a non-authenticated product. 7.The semiconductor device according to claim 6, wherein when determiningthat the battery cell is an authenticated product, the control unitcalculates the first shipping internal resistance, the second shippinginternal resistance, and the third shipping internal resistance again toperform the determination process.
 8. The semiconductor device accordingto claim 1, wherein the control unit multiplies a fourth normalizationcoefficient corresponding to a combination of the number of cycles, thetemperature, and the charging rate by the internal resistance tocalculate a fourth shipping internal resistance, and performs thedetermination process based on the fourth shipping internal resistance.9. The semiconductor device according to claim 8, wherein the controlunit derives the first normalization coefficient corresponding to thecounted number of cycles from the first reference informationassociating the number of cycles with the first normalizationcoefficient, derives the second normalization coefficient correspondingto the measured temperature from the second reference informationassociating the temperature with the second normalization coefficient,derives the third normalization coefficient corresponding to themeasured charging rate from the third reference information associatingthe charging rate with the third normalization coefficient, andmultiplies the first normalization coefficient, the second normalizationcoefficient, and the third normalization coefficient to derive thefourth normalization coefficient.
 10. The semiconductor device accordingto claim 8, wherein the control unit derives the fourth normalizationcoefficient corresponding to a combination of the counted number ofcycles, the measured temperature, and the measured charging rate fromfourth reference information associating the combination of the numberof cycles, the temperature, and the charging rate with the fourthnormalization coefficient.
 11. The semiconductor device according toclaim 10, wherein the fourth reference information includes a tableassociating a combination of the number of cycles, the temperature, andthe charging rate with the fourth normalization coefficient.
 12. Thesemiconductor device according to claim 10, wherein the fourth referenceinformation includes a function deriving the fourth normalizationcoefficient in which the number of cycles, the temperature, and thecharging rate are variables.
 13. The semiconductor device according toclaim 11, wherein the semiconductor device includes a fourth referenceinformation storing register storing the fourth reference information,wherein the fourth reference information is written into the fourthreference information storing register before the shipping of thebattery cell.
 14. The semiconductor device according to claim 8, whereinthe control unit compares the fourth shipping internal resistance withthe allowable range of the shipping internal resistance allowed as anauthenticated product, and when the fourth shipping internal resistanceis outside the allowable range, the control unit determines that thebattery cell is a non-authenticated product.
 15. The semiconductordevice according to claim 14, wherein when determining that the batterycell is an authenticated product, the control unit calculates the fourthshipping internal resistance again to perform the determination process.16. A semiconductor device comprising: a temperature measurement unitmeasuring the temperature of a battery cell; a voltage measurement unitmeasuring the voltage of the battery cell; an electric currentmeasurement unit measuring an electric current supplied from the batterycell; and a control unit, wherein the control unit measures the chargingrate of the battery cell based on the voltage, measures the internalresistance of the battery cell based on the voltage and the electriccurrent, and records the measured internal resistance into an internalresistance management table including a temperature recording axis and acharging rate recording axis based on the temperature and the chargingrate during measurement, and when the internal resistance at the sametemperature and the same charging rate is measured again, the controlunit compares the measured internal resistance with the correspondinginternal resistance recorded into the internal resistance managementtable to perform the determination process of whether the battery cellis a non-authenticated product.
 17. The semiconductor device accordingto claim 16, wherein the control unit calculates the difference betweenthe internal resistance measured again and the corresponding internalresistance recorded into the internal resistance management table, andcompares the difference with a difference allowable range allowed as anauthenticated product, and when the difference is outside the differenceallowable range, the control unit determines that the battery cell is anon-authenticated product.
 18. The semiconductor device according toclaim 16, wherein when the temperature recording axis corresponding tothe temperature during measurement is not provided in the internalresistance management table, the control unit calculates a temperatureinterpolation internal resistance based on the internal resistancecorresponding to the temperature during measurement on each of thetemperature recording axes corresponding to a plurality of thetemperatures near the temperature during measurement, calculates thedifference between the measured internal resistance and the temperatureinterpolation internal resistance, and compares the difference with thedifference allowable range allowed as an authenticated product, and whenthe difference is outside the difference allowable range, the controlunit determines that the battery cell is a non-authenticated product.19. The semiconductor device according to claim 16, wherein when thecharging rate recording axis corresponding to the charging rate duringmeasurement is not provided in the internal resistance management table,the control unit calculates a charging rate interpolation internalresistance based on the internal resistance corresponding to thecharging rate during measurement on each of the charging rate recordingaxes corresponding to a plurality of the charging rates near thecharging rate during measurement, calculates the difference between themeasured internal resistance and the charging rate interpolationinternal resistance, and compares the difference with the differenceallowable range allowed as an authenticated product, and when thedifference is outside the difference allowable range, the control unitdetermines that the battery cell is a non-authenticated product.
 20. Thesemiconductor device according to claim 16, wherein the semiconductordevice includes an internal resistance management table storing registerstoring the internal resistance management table, and wherein theinternal resistance management table is written into the internalresistance management table storing register before the shipping of thebattery cell.